Looks like Apple might have changed their mind and rushed a security update against Mac Defender a bit too quickly. "Hours after Apple released [the] update and the initial set of definitions, a new variation of Mac Defender is in the wild. This one has a new name, Mdinstall.pkg, and it has been specifically formulated to skate past Apple's malware-blocking code." Update: And one day later, Apple has updated its malware definitions to detect the new version. MD's turn.